In process control systems, such as distributed or popular scalable process control systems commonly found in chemical, petroleum, power generation, or other industrial processes, it is often necessary to reduce the pressure of a fluid. In some cases, the pressure of the fluid must be reduced significantly. In cases requiring a relatively high pressure reduction, the pressure drop ratio, which is the change in pressure divided by the inlet pressure, may be quite high.
Generally speaking, pressure reduction typically leads to increased levels of unwanted noise and/or vibration. In applications with a relatively high pressure drop, these problems can be even more pronounced. In an attempt to prevent or at least reduce noise and vibration, process systems often use flow restriction devices to reduce the pressure drop ratio and also to reduce the fluid pressures. Flow restriction devices include adjustable flow restriction devices, such as flow control valves and fluid regulators, and fixed fluid restriction devices, such as diffusers, silencers, and other back pressure devices. Conventional adjustable flow restriction devices, while effective, can be costly and difficult to install and maintain. Meanwhile, conventional fixed fluid restriction devices, though generally cheaper and easier to install and maintain, are typically not very durable. Various industrial, building, safety, and/or other codes often require the use of specific materials at external pressure boundaries. Because fixed fluid restriction devices typically form a portion of the external pressure boundary, fixed fluid restriction devices are usually built to the same code standards as the adjacent or surrounding piping, and hence the devices are typically made of the same material as the adjacent or surrounding piping. These materials, however, tend to be highly susceptible to erosion attributable to the fluid flowing through the system. This is particularly true when a fixed fluid restriction device is employed in a steam application that utilizes very erosive “wet steam” (water vapor and water droplets). The “wet steam” can quickly erode the fixed fluid restriction device, such that the fixed fluid restriction device may potentially have a relatively short life span.